haven't heard of a single complaint on it yet. So It appears so...As long as you follow the proper safety precautions. Anything can be painful if NOT sterile, or your method is not clean....Safety first. but I'm sure you already knew that.

No pain for me and its day 3 since injection. I also had 1-test mixed in there, and the only thing that happened was some slight discomfort in the delt, which most think is from injecting to deep. Quads had no pain. The only thing I could feel was some pain if I pushed on the inject site, otherwise I felt nothing. I also worked legs and delts day after I injected them with no problems.